Objective To study the effect of image processing on overall Wiener spectrum (WS) in a computed radiography system. Methods Imaging plate was exposed using conventional X-ray equipment. Overall WS sampling films were made by changing 3 parameters of spatial frequency processing, including frequency rang(RN), frequency type(RT), and degree of enhancement(RE), and by changing 1 of 4 parameters of gradation processing(rotation amount,GA).WS values were calculated by scanning on micro-densimeter for every film proceeded as discrete signal using fast Fourier transform. Results (1) The WS value of subscan direction was 7.26?10 -5 mm 2 when the spatial frequency was 1.0 LP/mm, it was 1.57 times larger than that of scan direction. The WS had peaks under high spatial frequency at sunscan direction. (2) The WS value of RN with 0 at scan direction was 7.90?10 -5 mm 2 when the spatial frequency was 1.0 LP/mm, it was 1.70 times larger than that of RN with 5, and 3.30 times larger than that of RN with 9. (3) The WS value of RE with 1.5 at scan direction was 1.05?10 -4 mm 2when the spatial frequency was 1.0 LP/mm, it was 2.27 times larger than that of RE with 1.0, and 2.92 times larger than that of RE with 0.5. (4) The WS value of GA with 1.5 at scan direction was 1.25?10 -4 mm 2 when the spatial frequency is 1.0 LP/mm, it was 2.70 times larger than that of GA with 0.8. (5) The WS value of RT with T at subscan direction was 9.80?10 -5 mm 2 when the spatial frequency was 1.0 LP/mm, it was 1.02 times larger than that of RT with F, and 1.35 times larger than that of RT with R, and also 1.55 times larger than that of RT with P. Conclusions RN, RE, and GA contributed strongly to Wiener spectra, but the contribution of RT was small. When processing the clinical images, adequate processing parameters should be chosen to reduce the image noise, so as to meet the clinical diagnostic need.

Objective To get the maximum information from computed radiography (CR) output images by changing post-processing parameters. Methods Six experimental photos of polypropylene balls of 2.0 mm in diameter were taken by means of one time X-ray exposing on an imaging plate (IP) with different post-processing parameters including rotation amount (GA), gray gradation type (GT), rotation center (GC), shifting amount (GS), frequency rank (RN), frequency type (RT), and degree of enhancement (RE). 6 photos were viewed by three students and one radiologist on a 6 000 lx illuminance viewbox. Receiver operating characteristic (ROC) curves were made by means of 5-value-differentiation method. Results The largest mean area value (Az) below ROC curves of a low contrast experimental photo with post-processing parameters GA=1.0,GT=A, GC=1.6, GS=0.3, RN=4.0, RT=R and RE=3.0 was 0.96, and the maximum information was obtained. The smallest mean area value (Az) was 0.78 with changed post-processing parameters GA=0.8, GS=-0.2 and RE=0.5 while other parameters were not changed. The minimum information was obtained from this photo. Conclusion In order to get the maximum information from a CR output image, the post-processing parameters should be suitably selected.

Objective To explore the clinical value of magnetic resonance imaging( MRI) in the diagnosis and classification of perianal abscess and anal fistula.Methods Eighty patients with suspected perianal abscess and anal fistula were selected in Yuyao People＇s Hospital from May 2016 to December 2017.They were divided into general examination group and MRI group by random number table,with 40 cases in each group. The general examination group underwent ultrasound examination,and the MRI group underwent MRI examination.The detection rate of MRI examination for various types of perianal abscess and anal fistula was analyzed based on the results of operation. Results In the general examination group, the diagnostic accuracy of anal fistula supervisor, anal fistula internal orifice,perianal abscess and anal fistula branch were 65.0% (26/40),70.0% (28/40),57.5% (23/40) and 52.5% (21/40),respectively,which in the MRI group were 92.5% (37/40),77.5% (31/40),87.5% (35/40) and 95.0% (38/40),respectively.There were statistically significant differences in diagnostic accuracy of anal fistula supervisor, perianal abscess and anal fistula branch between the two groups ( χ2 =9.054,7.116,8.865, all P <0.05). The effective rate of operation in the MRI group was 67.5% (27/40),which was significantly higher than that in the general examination group [67.5% (27/40)],the difference was statistically significant(χ2 =9.935,P<0.01). Conclusion Using MRI to diagnose perianal abscess and anal fistula can accurately judge the number,involvement range,specific location and surrounding structure of the abscess and anal fistula,and has important value for clinical treatment and prognosis.

Objective:To investigate the efficacy of digital subtraction angiography combined with wire guidance versus gastroscopy in enteral nutrition catheterization in patients with special diseases of the upper gastrointestinal tract. Methods:We recruited 120 patients with special diseases of the upper gastrointestinal tract who underwent enteral nutrition catheterization in Yuyao People's Hospital from January 2016 to July 2020. These patients had gastric outlet obstruction ( n = 40), esophageal obstruction ( n = 39), tracheoesophageal fistula and mediastinal-esophageal fistula ( n = 26), or anastomotic fistula or anastomotic stenosis ( n = 15) after esophageal and gastric surgery. They were randomly allocated into the control and study groups ( n = 60/group). The control group was subject to enteral nutrition catheterization under the guidance of gastroscopy. The study group was subject to enteral nutrition catheterization using digital subtraction angiography combined with wire guidance. We compared the success rate of enteral nutrition catheterization, the time to successful enteral nutrition catheterization, changes in vital signs (such as heart rate, respiratory rate, mean arterial pressure, and blood oxygen saturation) after catheterization relative to before catheterization, and the incidence of adverse reactions between the two groups. Results:The success rate of enteral nutrition catheterization was significantly higher in the study group than in the control group (86.67% vs. 65.00%, χ2 = 7.68, P = 0.006). The time to successful enteral nutrition catheterization in the study group was significantly shorter than that in the control group [(28.61 ± 3.37) minutes vs. (39.75 ± 4.61) minutes, t = -8.92, P < 0.001]. During enteral nutrition catheterization, heart rate, respiratory rate, and mean arterial pressure in the control group were significantly increased compared with before enteral nutrition catheterization ( t = 5.07, 6.85, 4.96, all P < 0.001). During enteral nutrition catheterization, the heart rate and respiratory rate were significantly higher in the control group than in the study group ( t = 3.45, 3.29, both P < 0.001). After enteral nutrition catheterization, the incidence of adverse reactions was significantly lower in the study group than in the control group (13.33% vs. 33.33%, χ2 = 6.70, P = 0.010). Conclusion:Digital subtraction angiography combined with wire guidance can increase the success rate of enteral nutrition catheterization in patients with special diseases of the upper gastrointestinal tract, shorten the time to successful enteral nutrition catheterization, increase patient tolerance to catheterization, and reduce adverse reactions.